Norwich — Police have arrested four people in connection with two major fires at vacant homes in the city, including a woman who was on probation after serving jail time for her role in the Capehart Mill fire.

Each was charged with two counts of first-degree arson, two counts of third-degree burglary and two counts of first-degree criminal mischief.

The four are accused of using gasoline to set the two fires, causing more than half a million dollars in damages, putting emergency responders at risk and displacing more than two dozen people.

On March 26, city firefighters battled a blaze at a vacant house at 7-9 Oak St. That fire damaged two other houses and displaced 27 people. Two City of Norwich firefighters suffered injuries that required treatment, according to police. Total damages to the houses are estimated at more than $500,000.

Three days later, city crews responded to a fire at 11 Lake St., which caused extensive damage to the home. No one was displaced in that fire. Damages are estimated at $75,000.

Norwich Patrolman Robert L. Smith wrote in an arrest warrant affidavit that, "due to the magnitude of (the Oak Street) fire, fire and police resources were quickly strained, posing an extremely dangerous situation for firefighters and police officers who had to quickly act and evacuate residents of the involved buildings." He also referenced the financial and personal losses suffered by the residents.

According to the affidavit, police initially identified the suspects by interviewing Ortiz, a 24-year-old city man who had reported the Lake Street fire. Without implicating himself, Ortiz said Markham told him that he and Fauquet had set the fires because Fauquet was "mad about something."

Police interviewed Fauquet, who admitted that he and Markham had started the fire. But Markham denied his involvement and confronted Fauquet for "snitching" on him and was arrested for causing a disturbance, according to police.

A witness then came forward and told police that MacDonald had been involved, and police corroborated the information with Fauquet, according to the warrant. The witness also told police she saw the three men after the Lake Street fire and they were covered in soot and smelled like smoke.

Confronted by Smith, the patrolman, about the Oak and Lake street fires, MacDonald pulled a Bic lighter from her pocket, handed it to Smith and said, "Here, take this from me. I am violating my probation by having this with me." MacDonald then became uncooperative and terminated the interview, according to the arrest warrant.

MacDonald is on probation for her role in the Capehart Mill fire in April 2010, where she was one of six charged with setting fire to the abandoned mill.

According to police, MacDonald, Ortiz's brother Ramon Ortiz, and Kevin Walker climbed a chain-link fence topped with barbed wire to gain entry to the mill, then used gasoline to start fires at three points. Three others watched or served as lookouts.

MacDonald has a lifelong history of mental illness, and while she was found competent to stand trial, prosecutor David J. Smith said the state offered her a plea deal of a year in prison based on her mental capacity. She fell under the sway of other people, particularly Walker, a self-confessed serial arsonist, Smith said.

At her arraignment Wednesday, Judge Hunchu Kwak ordered her held in lieu of $600,000 bond. The three other men are expected to be arraigned today.